1910.] 



Galactose by Yeast and Yeast -juice. 



647 



III. Famentation of Galactose by Yeast-Juice. 

 The juice was obtained from S. Carlsberg I cultivated in the medium 

 described above. The yeast was well washed with water and then ground in 

 the usual manner. 



Experime7it 12. — Two quantities of 20 c.c. juice, to one of which 1 gramme 

 of galactose had been added, were incubated at 25° in presence of toluene. 



Experiment 13. — Three quantities of 25 c.c. of a different juice were 

 incubated as above ; to one was added 2 grammes galactose, to the second 

 2 grammes glucose, and to the third 1 c.c. H2O. 



Table III. — Fermentation of Galactose by Yeast Juice obtained from Trained 



S. Carlsberg I. 



Experiment. 



Fermentation in 1 hour. C.c. of CO2 evolved. 











Galactose. 



Autofermentation. 



Glucose. 



12 



49-0 



8-4 





13 



39 -3 



8-6 



25 -7 



These experiments clearly show that galactose is readily fermented by the 

 juice obtained from yeast which has acquired the property of fermenting this 

 sugar. 



IV. Total Fermentation of Galactose and Glucose hij Yeast-juice. 



Experiment 14. — Two quantities of 25 c.c. of the same yeast-juice as used 

 in Experiment 13 were incubated with 2 grammes galactose and 2 grammes 

 glucose respectively in presence of toluene. 



The initial rate of the galactose solution was higher than that of the 

 glucose, but the total volume of gas evolved was slightly greater in the case 

 of glucose. Fermentation had ceased in both cases after 19 hours. 



Table IV. — Total Fermentation of Galactose and Glucose by Yeast-juice 

 from Trained S. Carlsberg I. 



Initial rate. 

 C.c. in 0 minutes. 



Total fermentation. 



Ratio of totals. 



Galactose. 



Glucose. 



Galactose. 



Glucose. 



Galactose. 



Glucose. 



3-7 



3-1 



94-9 



99-2 



0-95 



1-00 



